-- CTB Polo Limited has been granted a $9.8 million construction loan by International Savings and Loan Association, to build 80 townhomes at the Polo Club in Boca Raton. The community features equestrian trails and stables, tennis courts and golf courses.

-- The Edward J. DeBartolo Corp., the Youngstown, Ohio, developer and manager of shopping malls, has purchased 100 percent interest in the Mayfair development in Miami`s Coconut Grove.

-- Florida Atlantic University Small Business Development Center has relocated to University Tower, 220 SE Second Ave., Fort Lauderdale, phone 355-5211.

-- Florida International University Small Business Development Center has relocated to the World Trade Center, Room 217, 1800 Eller Drive, Port Everglades, phone 987-0100.

-- Greenbrook Equestrian Village, within the Palm Beach Polo & Country Club in West Palm Beach, has completed construction on the stables and jump course and is beginning construction on the residential compound. Developer of the 16- acre project is Greenbrook Equestrian Center Inc.

-- Gulfstream Micro Systems, Boca Raton, a micro computer and peripheral manufacturer, has introduced EZ-Fax, a PC compatible facsimile product that can send and receive documents to and from any Group III facsimile machine.

-- Hatteras of Lauderdale, a yacht dealership, has opened a new service center at 401 SW First Ave., Fort Lauderdale.

-- Inter-American Imports of Palm Beach Inc., West Palm Beach, an import company, has been formed by Anthony Landon and Hyman and Erntrudt Rabin, to act as exclusive agent for Radenska (Three Hearts) Mineral Water, bottler and distributor of sparking mineral water.

-- Langstroth Mortgage Co., Fort Lauderdale, has arranged an $11.58 million loan for construction of Palm Springs Plaza, a shopping center at the northeast corner of Coral Springs Drive and Royal Palm Boulevard in Coral Springs; and has arranged a $7.2 million loan for construction of Sanford Town Square, a shopping center in Sanford.

-- Las Casas, a community of Spanish-style estate homes and villas, is to be constructed on a 40-acre site on Military Trail in Boca Raton. Co-developers are Paul Hennes and Manuel Dougnac.

-- Royal Palm Travel Inc., a travel agency, has signed a lease for office space at 223 Sunset Ave., Town of Palm Beach.

-- Ryder System Inc., Miami, has announced the acquisition of the following privately held school bus companies: St. Paul & Suburban Bus Co., Minnesota; Klines School and Charter Bus Co., Illinois; and George H. Hoenes Jr. Inc., New Jersey. The companies are engaged in school bus contracting, commercial contracting and charter services.

-- Subway Development Corp., Fort Lauderdale, has opened its first Subway Sandwiches and Salads store in Nassau, Bahamas.

-- The Thomas Cos., West Palm Beach, has leased 14,000 square feet to the Department of Environmental Regulation in the 1900 Building, an office/retail building under construction at the corner of Forest Hill Boulevard and Congress Avenue in West Palm Beach.